RP-HPLC-UV Method for Simultaneous Estimation of Ceftriaxone

RP-HPLC-UV Method for Simultaneous Estimation of Ceftriaxone A Validated RP-HPLC-UV method for Simultaneous estimation of Ceftriaxone and Sulbactum in Rat Plasma ABSTRACT: A reverse phase-liquid chromatographic method with UV detection is developed for simultaneous estimation of ceftriaxone sodium and sulbactam sodium in rat plasma. Drugs were extracted from blank plasma by simple protein precipitation technique. Chromatographic separation of these two drugs was done on Phenomenex C18 column (250mm X 4.6mm, i.d, 5ÃŽ ¼m) by using mobile phase consisting of 10mM potassium dihydrogen orthophosphate buffer (pH- 5) and acetonitrile (90:10 % v/v). The developed RP-HPLC method had the acceptable symmetrical peaks good resolution and drugs were eluted with good retention time. The developed bio-analytical method was Linear, precise, and accurate with the concentration range of 20-150 ÃŽ ¼g mL-1 for ceftriaxone and 10-75 ÃŽ ¼g mL-1 for sulbactam. From the developed method we can moniter ceftriaxone and sulbactam sodium concentrations in rat plasma. Keywords: Ceftriaxone sodium, Sulbactam sodium, Liquid chromatography, Rat plasma INTRODUCTION Ceftriaxone[1] (CFX) is a third generation cephalosporin. Chemically it is (6R,7R)-7-{2-(2-amino-4-thiazolyl)-(Z)-2- [methoxyiminuteo-acetamido]-3{[(2,5-dihydro-6-hydroxy-2-methyl-5-oxo-as-triazin-3-yl)thio]methyl}-8-oxo-5-thia-l-azobicyclo [4,2,0] oct-2-ene-2-carboxylic acid. Sulbactam (SBM) chemically (2S,5R)-3,3-Dimethyl-7-oxo-4-thia-1- azabicyclo[3.2.0] heptane -2-carboxylic acid 4,4-dioxide is used as a beta-lactamase inhibitor. Structural formulae of CFX and SBM are given in Fig.1. These drugs are frequently associated in pharmaceutical formulations against meningitis, typhoid, gonorrhoea and urinary tract infections [2]. Sulbactomax is a commercially available pharmaceutical product containing SBM and CFX. The product is available as a dry powder for injection. The product is supplied in different strengths (250 mg+125 mg, 500mg+250 mg, 1gm+0.5gm, 2gm+1gm) of CFX and SBM respectively. Fig.1.Chemical structure of CFX and SBM Sulbactomax is a synergistic antimicrobial mixture with clear in vitro antibacterial activity against a wide spectrum of organisms. SBM not only increases the antibacterial activity of CFX but also shows a moderate antibacterial activity by forming a protein complex with beta-lactamas by irreversibly blockin their destructive hydrolytic activity. Thus, SBM increases the spectrum of activity of CFX. This SBM also binds with some penicillin binding proteins, sensitive strains are often considered more susceptible to the Sulbactomax than CFX alone. In bacterial strains that produce either low amounts of beta lactamase, or none at all, a synergistic effect is witnessed when SBM is associated with CFX that has a complementary affinity for the target sites. Sulbactomax has good active against all the microorganisms which are sensitive/resistant to CFX. Further, it also demonstrates synergistic activity (decrease in minimum inhibitory concentrations for the combination versus those of each component) in a variety of organisms. So it has improved efficacy as compared to CFX alone, lesser side effects, wider spectrum coverage and better results of bacterial MIC (minimum inhibitory concentration) makes this product unique in the world. A literature survey revealed a spectrophotometric [3], spectrofluorimetric in human plasma [4], HPLC for the estimation of marketed formulations [5,6], in human plasma [7] and for the determination of pharmacokinetics in dogs [8], capillary electrophoresis [9] and GC-MS [10] methods for the estimation of CFX and SBM individually and in combined forms. However, from the literature survey there was no method development reported for the simultaneous estimation of CFX and SBM by HPLC in rat plasma. The present communication describes an isocratic liquid chromatography (LC) method for simultaneous determination of CFX sodium and SBM, which can be used for the quality control of the formulation developed and other biological applications. Experimental Chemicals and Reagents All chemicals and reagents used were of analytical grade only. Milli-Q-water was used throughout the process and acetonitrile of HPLC grade were procured from Merck Chemical Laboratories, Bangalore, India. Commercial formulation, CetriaxS injection containing ceftriaxone sodium 1gm and sulbactam sodium 0.5 gm were obtained from the local market. Blank rat plasma was obtained from JSS Medical College and Hospital, Mysore, India. Instrumentation and Analytical Conditions A HPLC with the UV detector was used for this research work. Here the separation was done using Phenomenex C-18 column. The mobile phase was a mixture of phosphate Buffer (pH adjusted to 5 with potassium hydroxide) and acetonitrile (90:10) v/v. The mobile phase was filtered through 0.45 ÃŽ ¼ membrane filter before its use, degassed with a helium sparge for 15min at flow rate of 1.0 mL min-1. The column was maintained at room temperature 20 ±100C. The injection volume of samples was 10 ÃŽ ¼L. The analyte was monitored at wavelength of 230 nm and optimized chromatographic conditions are shown in Table-1. 2.3.Preparation of mobile phase: Phosphate buffer of pH 5 was prepared by dissolving 1.36 gm ofPotassiumdihydrogenorthophosphate in 1000 mL of water and it was sonicated for 5 minutes, then the pH was adjusted using potassium hydroxide solution. It was than filtered by vaccum filteration. Finally the mobile phase was prepared by mixing phosphate buffer and acetonitrile in the ratio 90:10v/v. 2.4.Preparation of standard and sample solution SeparatelyweighedquantityofCFXsodium(10mg)andSBMsodium (10mg)was transferred into a 100mL volumetricflaskandmadeupto100mLwithwatertoget100  µg mL-1 ofCFXsodiumand100  µg mL-1 ofSBM. From this, different solutions containing the mixture of CFXsodium(20-150  µg mL-1) and SBMsodium(10-75  µg mL-1) were prepared. For the preparation of sample solution, Cetriax-Spowder for injection(containing1gmof CFXand0.5gmof SBM)was transferred to a 100 mL volumetric flask. Distilled water was added, and then swirled to dissolve it, diluted to 100 mL with the same solvent. 2.5.Preparation of calibration curve: Five different concentrated solutions containing mixture of CFX (20-150  µg mL-1) and SBM (10-75  µg mL-1) were injected onto HPLC. A calibration curve was prepared taking concentrations on X-axis and Peak Area on Y-Axis. 2.6.Preparation of plasma samples: Plasma samples of CFX and SBM was prepared by the protein precipitation method. A blank was prepared by taking 0.1mL of rat plasma and to this 1.9 mL of acetonitrile was added and sample was prepared by taking 0.1 mL of combination of CFX and SBM (which were mixed in equal volumes) and 0.1 mL of rat plasma was added to the 2 mL Eppendorf tubes containing 1.8 mL of acetonitrile. These samples were centrifuged for 10 min at 10,000 rpm. The supernatant solution filtered through 0.45 µ syringe filter and transferred to HPLC vials. RESULTS AND DISCUSSION 3.1 Method Development Taking into consideration, the instability of CFX and SBM in strong alkaline and strong acidic condition, the pH value of the mobile phase should be limited within the range of 3à ¢Ã¢â€š ¬Ã‚ 7, since mild acidic pH favours the retention and separation of two drugs on Cà ¢Ã¢â€š ¬Ã‚ 18 column. After few trials, phosphate buffer with pH 5 was finalized. The method development started with the methanol and phosphate buffer as drugs did not elute in this mobile phase, so the organic phase was altered from methanol to acetonitrile. Both CFX and SBM in the mobile phase have no significant UV maximum, the wavelength of 230 nm was employed for the detection. After few trails Phenomenex C-18 column and binary mixture of phosphate buffer (pH 5) and acetonitrile (90:10 % v/v) was optimized as mobile phase which produced symmetric peak shape, good resolution and reasonable retention time for both the drugs (Table 1). The retention times of CFX and SBM for six repetitions were found to be 7.8  ± 0.02 min and 4.7  ± 0.006 respectively (Fig.2). (a) (b) Fig.2. LC chromatogram of rat blank plasma (a) plasma spiked with standard CFX and SBM(b) Table 1. Optimized chromatographic conditions Parameter Optimized condition Chromatograph HPLC with UV- detector Column C18 Column Mobile Phase Acetonitrile and pH-5 buffer in the ratio of 10:90(v/v) Flow rate 1.00 mL min-1 Detection 230nm Injection volume 10 ÃŽ ¼L Temperature column Room temperature 3.2.Method validation Validation is a process of establishing documented evidence, which offers a high degree of assurance that a specific activity will steadily yield anticipated result or product meeting its predetermined specifications and quality features [11]. The method was validated for different parameters like linearity, precision, recovery, accuracy, selectivity and sensitivity [12]. 3.2.1Selectivity Selectivity is defined as, the capability of an analytical method to distinguish and measure the analyte in the presence of other components in the sample [12]†. Selectivity is calculated by injecting extracted blank plasma and relating with the response of extracted LLOQ samples. Both the peaks of Ceftriaxone and Sulbactum did not interfere with any endogenous components. 3.2.2Sensitivity Sensitivity is measured using Lower Limit of Quantification (LLOQ). LLOQ is the lowest concentration of the standard curve that can be measured with acceptable accuracy and precision [12]†. The LLOQ was established using five samples independent of standards and determined the co-efficient of variation and appropriate confidence interval. 3.2.3.Linearity of Response To demonstrate the linearity of response, series of solutions ranging from (20-150  µg mL-1) of CFX and SBM of (10-75  µg mL-1) were prepared and injected onto the HPLC system following the described conditions. The graph was constructed between concentration vs. peak area and it was found that correlation co-efficient and regression analysis were within the limits and the results are summarized in the Table 2, and the calibration graphs are shown in Fig. 3 and Fig. 4 for CFX and SBM respectively. Fig.3. Calibration graph of CFX Fig.4. Calibration graph of SBM Table 2. Linearity of CFX and SBM Parameters CFX SBM Retention time (min) 7.3 4.6 Linear range (ppm) [n=6] ( µg mL-1) 20-150 10-75 Correlation coefficient (r2) 0.996 0.997 Slope 1513.1 155.58 Intercept 272333 61596 Lowest limit of quatification LLOQ ( µg mL-1) 0.87 0.96 3.2.4.Recovery â€Å"The recovery of an analyte is the detector response achieved from an quantity of the analyte added to and extracted from the biological matrix, correlated to the detector response found for the true concentration of the pure authentic standard†[12]. â€Å"Recovery of the analyte is not necessary be 100%† [12]. This experiments were performed by comparing the analytical results for extracted samples at three different concentrations (low, medium, and high) with unextracted standards that represent 100% recovery. Results are summarised in Table 3. Table 3. Recovery studies of CFX sodium and SBM Concentration of CFX and sulbactam Amount recovered% for CFX Amount recovered% for SBM Low 98.7% 99.9% Medium 96.8% 98.9% High 99.3% 98.6% 3.2.5.Accuracy and Precision For validation of this bioanalytical method, precision and accuracy should be determined using minimum of five determinations per concentration level (excluding blank samples). The mean value should be within  ± 15% of the theoretical value, except at LLOQ, where it must not differ by more than  ± 20%. The accuracy and precision around the mean value should not be beyond 15% of the CV except for LLOQ, where it should not exceed by 20% of the CV. The accuracy of the analytical method defines the closeness of agreement between the test value and the reference value. The precision of the analytical method describes the closeness of frequent individual measures of analyte. Accuracy is expressed in terms of % obtained. Precision is expressed in terms of coefficient of variation (CV). The statistical method for determination of the accuracy and precision should be predefined and calculated according standard practise. Accuracy and Precision should be demonstrated for the low, medium, high and LLOQ QC samples, within a single run and between different runs results are summarised in Table 4 5. % CV (precision) =100 x Standard deviation/Mean Table 4. Accuracy and Precision of CFX Theoretical concentration ( µg/mL) Measured concentration ( µg/mL) Intra-day Inter-day %CV Accuracy (%) %CV Accuracy (%) 20 0.98 98.4 1.42 96.1 100 0.76 103.7 1.32 102.3 150 1.34 99.5 1.7 98.7 Table 5. Accuracy and Precision of SLB Theoretical concentration  µg mL-1 Measured concentration ( µg mL-1) Intra-day Inter-day %CV Accuracy (%) %CV Accuracy (%) 10 0.96 101.7 0.76 95.6 50 1.00 99.8 1.2 103.4 75 1.02 97.3 1.04 97.4 3.2.6.Stability studies Freeze and Thaw Stability Stability of analyte was determined with three freeze and thaw cycles. All the three aliquots at low, medium and high concentrations were stored at the proposed storage temperature for 24 hours and defrosted unassisted at room temperature. When completely thawed, the samples were again frozen for 12 to 24 hours under the same conditions. The same cycle was repeated two more times, and then analyzed after the third cycle. Short-Term Temperature Stability Three aliquots of low, medium and high concentrations were thawed at room temperature and at this temperature sample was kept from 4 to 24 hours and analyzed. Long-Term Stability The storage time in a long-term stability assessment should surpass the time between the date of first sample collection and the date of last sample analysis. Long-term stability was determined by storing three aliquots of the low, medium and high concentrations under the same conditions as that of the study samples. The concentrations of all the stability samples were related to the mean of back-calculated values for the standards at the suitable concentrations from the first day of long-term stability testing. Stock Solution Stability The stability of stock solutions of drug was estimated at room temperature for 6 hours. After the desired storage time, the stability was confirmed by comparing the instrument response with that of newly prepared solutions Results are summarised in Table 6. Table 6. Stability studies of CFX and SBM Stability  µg mL-1 (error %) CFX  µg mL-1 (error %) SBM 20 100 150 10 50 75 Freeze-thaw 84.5 93.3 94.9 88.5 96.3 97.9 Long term 100.5 100.6 100.8 100.5 101.6 100.8 Short term 93.9 97.6 101.4 93.9 93.6 103.4 Stock Solution 95.6 97.6 93.2 95.3 96.8 98.5 SUMMARY In this work, a simple, stability indicating, accurate and validated stability indicating HPLC method for the simultaneous determination of ceftriaxone and sulbactam in their pharmaceutical formulation was developed. The method was validated according to FDA guidelines. CFX and SBM were eluted at 7.3 min and 4.6 min respectively. The correlation coefficient (r2) for CFX and SBM were found to be 0.996 and 0.9976 respectively. Lower Limit of quantification (LLOQ) was found to be 0.87  µg mL-1 for ceftriaxone and 0.96  µg mL-1 for sulbactam. The %CV for the intraday and interday precision were found to be CONCLUSION The method includes simple and precise method for simultaneous determination of CFX sodium and SBM. It produces symmetrical peak shape, good resolution and reasonable  retention time for both drugs. So this method can be appropriate for the   simultaneous estimation of CFX sodium and SBM in quality control studies for routine analysis. AKNOWLEDGMENT The authors are thankful to The Principal, JSS College of Pharmacy, JSS University, Mysore for providing all necessary facilities to carry out the research. The authors are also thankful to Strides Arco labs, Bangalore for providing the pure salbactum sodium and ceftriaxone sodium as gift samples. References Rang HP, Dale MM (1993). Pharmacology, (2nd ed.). Churchill Livingstone, ELBS. Physicians Desk Reference (1997). American Academy of Physician Assistants (51th ed). Patel FM, Dave JB , Patel CN, spectrophotometric methods for simultaneous estimation of cefuroxime sodium and sulbactam sodium in injecton, International journal of pharmaceutical sciences and research.2012; 3(9), 3513-3517. Jasmin Shah,Rasul Jan M,Sultan Shah,Naeem M, Spectrofluorimetric Protocol for Ceftriaxone in Commercial Formulation and Human Plasma After Condensation with Formaldehyde and Ethyl Acetoacetate, Journal of Fluorescence.2011; 21(6), 2155-2163. Shrivastava SM, Singh R, Ariq A, Siddiqui MR, Yadav J, Negi PS, Chaudhary M, A novel high performance liquid chromatographic method for simultaneous determination of ceftriaxone and sulbactam in sulbactomax, Inter Journal of Biomed Sci. 2009; 5(1), 37-43. Durairaj S, Annadurai T, Palani Kumar B, Arunkumar S, Simultaneous Estimation of Ceftriaxone Sodium and Sulbactam Sodium using Multi-Component Mode of Analysis, Inter Journal of ChemTech Research. 2010; 2(4), 2177-2181. Huang Ying, Liang Maozhi, Yu Qin, Jiang Lei,Shi Yingkang, Determination of ceftriaxone in human plasma by HPLC, Chinease Journal of Antibiotics.2000; 25,109. Zhao Xi, Zhang Dan, Chen Hong, Determination of cefotaxime/sulbactam in plasma and pharmacokinetics in dogs by high performance liquid chromatography. Zhongguo Kangshengsu Zazhi. 2004; 29(10): 614-616. Jelinek I, Krejcirova H, Dohan J, Roubal Z, Determination of sulbactam in human serum using capillary electrophoresis,Cesk Farm.1990; 39,305–307. Foulds G, Gans DJ, Girard D, Whall TJ, Assays of sulbactam in the presence of ampicillin.Therm Drug Monit.1986;2,223–237. Lloyd RS, Joseph JK, Joseph LG (1997). Practical HPLC Method Development (2ndedition) New York: Wiley-Blackwell. FDAUS. Guidance for Industry: Bioanalytical Method Validation. Rockville, MD, USA: US Department of Health and human services, US FDA/Center for Drug Evaluation and Research; 2001.

America

Dry. Genera Bole As Americans we strongly believe in having the right to do what we please. After all, this is a free country. So if we want to smoke around our kids, build a fast food diet, or Just be plain lazy we can go right ahead and do it and who will tell us otherwise? No one. We can continue to slowly kill ourselves through all of our bad habits and ignorance in health and then pass on this gift onto our children. Something needs be done soon before it is too.Americans should take better care of their health by developing better eating habits, focusing on future health issues, and y not being so lazy. It is no secret that America is look at as a fat country. If other countries were to compare themselves with us they might represent the USA with a big McDonald's symbol or something similar. And for good reason. With fast food being so convenient and Just about anywhere it is so easy to a busy American to Just use that drive though and the Burger King and pick up some food.Ther e is no second guessing something easy that tastes good. Say an American doesn't eat so much fast food and shops for themselves. Just look at the prices of Junk or processed food in comparison to organic and healthier food. How can it be possible to sell something with added chemicals cheaper than something off the earth? According to the U. S. Department of Health and Human Services (KIDDUSH) and the Centers for Disease Control and Prevention (CDC), there has been a dramatic increase in obesity in the United States over the past 20 years .Similarly, in 1990, no state had obesity rates higher than 15%. By 2005, only 6 states had an obesity rate less than 20%. Obesity has been directly linked to hypertension, diabetes, cancer, and depression. Each year, over 300,000 adults in the U. S. Will die from obesity related causes. Minefield, Charles E, Peeved profile; Dotty, Nicole, MPH; Fletcher, Autumn, PhD, APRON, CUFF-BC. BAND Journal. 3 (Summer 2008): 83-8. Although It is understandable that lower income families don't have the funds to buy all the organic food.In 2011, the low-income threshold for a family of four with two children was $45,622. Between 2007 and 2011, the share of working families who are low income increased from 28 percent to 32. 1 percent (Annie e. Casey 2014). In 2011, the top 20 percent of working families received 10. 1 times the total income received by the bottom 20 percent of working families, up room 9. 5 in 2007. The same goes for busy families who are Just looking to eat whatever is easiest. Is America targeting certain families? Is there more money in junk than in organic food?Or is it Just the ignorance of a people not concerned about future health. Issues in health later on in the future seem to be at the bottom of the charts when it comes to what Americans worry about. It is all about the here and now that's important. That is until someone comes down with a life altering health issue. â€Å"We cannot treat our way out of the canc er problem,†. New cancer cases will rise from an estimated 14 million annually in 2012 to 22 million within two decades. Over the same period, cancer deaths are predicted to rise from 8. Million a year to 13 million â€Å"More commitment to prevention and early detection is desperately needed in order to complement improved treatments and address the alarming rise in cancer burden globally. † By Tim Hum and Jean Christensen, CNN Feb. (2014). It seems as though the only time health is important is when life is at stake. The crazy thing is, life was at stake and being damaged from the day any harmful substance was consumed or a bad habit was formed. Today's youth has a mindset of live fast die young but it is not entirely their fault for having this thought process.It's the fault of the generation before them. Our youths parents or anyone who the they look up to is to blame because chances are that generation had bad health habits and passed it down whether they knew it o r not. Today's children have lost the ability to pretend and imagine. This is most definitely to no fault of their own. Children do not have to create their own fantasy worlds because they have an pad, a big screen TV or a WI to do it for them. Taylor Finn, Iowa State Daily (2014). What we do know will affect us later on in life and in some cases might even effect someone else.Forming unhealthy habits doesn't stop at diet choice, ignorance, or lack of caring. Finding an easier way for things causes a bigger issue. And that issue is Laziness. Too much of our lives too easy. In fact, everything is made to be easier or shrouded with the word â€Å"convenience†. Americans can Just go to a drive through for food or even order food and there is no need to even get out of the house. Media has taken over the life of Americans as well. Americans of all ages these days cannot stray too ar away from their home for fear of their smart phone dying or there not being any Wi-If.Youth spend their days behind tablets, televisions, and smart phones rather than using imagination outside or being active. Videotapes can be looked at as a way to pass the time but for our youth it could possibly be causing them to be desensitizing to the world and can hinder their ability to use their own imagination for entertainment. America is focused on the easy way out of things rather than taking the time out to educate themselves about lifestyle, diet, and exercise. If it squires activity outside of the normal sedentary house life it is almost shunned and thought of as nonsense.Without the will to understand and learn about what a good diet is, how to make changes to avoid future health issues, and how to get away from the normal lazy lifestyle America will continue its downward spiral in to cancers, a poisoned youth, and obesity. Simple things like looking at the ingredients of food normally consumed, or getting out once in while Just walk for a half hour can be enough to chance a lif estyle. We as Americans need to find a way for lower income families to be able to arches food healthier to themselves and more importantly their kids.Many families are very busy and have no time to think of the issues of grab and go foods and should consider creating a plan to eat better while on the move. Most important is America's youth. Higher intake of sugar-sweetened beverages is associated with increased IBM and considered a contributing factor of childhood obesity. From 1989 to 2008, there has been a significant increase in total per capita consumption of sugar-sweetened beverages, from 130 to 212 collieries (kcal) per day, in children 6- 1 years of age.Placing an emphasis on reducing the empty energy intake from sugar-sweetened beverages and increasing the intake of nutrient-dense beverages, such as low-fat milk, is an essential component to decreasing the prevalence of obesity in children. Higher levels of education and positive parental behaviors, such as parent support and limiting weekly fast-food intake, are associated with lower intakes of sugar-sweetened beverages. Current Opinion in Endocrinology & Diabetes and Obesity (2013) Why should our youth suffer from the actions of the current enervation when simple changes can make a difference In our future.

Does 16 and Pregnant Promote or Prevent Pregnancy? Essay

Many have seen or heard of the television series â€Å"16 and Pregnant.† In 2009 this series began with the intention to show teens how difficult it is to be a parent. While â€Å"16 and Pregnant† has been playing for many years now, the debate has been sparked whether the show promotes or prevents pregnancy. Many people think that â€Å"16 and Pregnant† promotes pregnancy. The show makes being a parent look more glamorous then difficult. They make it look easier and even more â€Å"fun† to be a teenage parent. Many teenagers who watch the show see girls becoming more and more famous. The girls start other shows or even end up in magazines. When young people see this it makes them think that they could become famous if they have a child. The show gives teenagers false hope that they will also get to be on a TV show if they have a baby at a young age. As the show goes on you see the teen parents with new houses, cars, and even new wardrobe and style. The â€Å"16 and Pregnant† stars get paid at least $75,000 a season depending on their contract. When teenagers see all the new things that they could have they get the idea that getting pregnant could reward them with many new things. The stars say they can’t finish school, and get a job because of the difficulty of caring for a child interferes with their time to do so. With the salary that they have they don’t have to worry much about getting a job. Teenagers might not want to have to work so they will think that if they get pregnant they won’t have to worry about it. When teenagers see the stars in magazines they will want to get pregnant so they could also be in magazines and on multiple shows. I believe that â€Å"16 and Pregnant† prevents pregnancy. The show is mostly accurate in showing how parenting is. It shows the actual difficulties of being a parent or having to deal with the decision of adoption. The young parents have to come to unwanted agreements with their child’s other parent and deal with custody through courts. It also shows how babies and children actually act and how difficult it is to take care of a child. There has  been an increase in the use of birth control and a drop in the amount of teenage births. â€Å"Social networking posts including the words ‘birth control’ increased by 23 percent.†(Kristof) Internet searches on birth control also increased. Regions where the show is watched more had â€Å"more of a drop in teen births† and there is overall â€Å"20,000 fewer teen births each year.†(Kristof) Those who say â€Å"16 and Pregnant† promotes pregnancy can agree that there has been an increase in the use of birth control. Also they can agree that there has been a decrease in teen pregnancy cases. Although these are true, there could be a different factor correlated to the increase in use of birth control. With an increase in the use of birth control there has been less cases of teen pregnancy. Many schools have sex education which helps teenagers understand the use of contraception. This could be a factor of the increase in birth control. Also, after watching â€Å"16 and Pregnant† many teenagers may have been persuaded to start using contraception. The increase of contraception use is preventing more teenagers from becoming pregnant. Reference Kristof, Nicholas. â€Å"TV Lowers Birthrate (Seriously).† The New York Times. The New York Times, 19 Mar. 2014. Web. 25 Mar. 2014.

Facts and Characteristics of Rodents

Rodents (Rodentia) are a group of mammals that includes squirrels, dormice, mice, rats, gerbils, beavers, gophers, kangaroo rats, porcupines, pocket mice, springhares, and many others. There are  more than 2000 species of rodents alive today, making them the most diverse of all mammal groups.  Rodents are a widespread group of mammals, they occur in most terrestrial habitats and are only absent from Antarctica,  New Zealand, and a handful of  oceanic islands. Rodents have teeth that are specialized for chewing and gnawing. They have  one pair of incisors in each jaw (upper and lower)  and a large gap (called a diastema) located between their incisors and molars. The incisors of rodents grow continuously  and are maintained through constant use—grinding and gnawing wears away the tooth so that is always sharp and remains  the correct length. Rodents also have one or multiple pairs of premolars or molars (these teeth, also called cheek teeth, are  located towards the back of the animals upper and lower jaws). What They Eat Rodents eat a variety of different foods including leaves, fruit, seeds, and small invertebrates. The cellulose rodents eat is processed in a structure called the  caecum. The caecum is a pouch in the digestive tract that houses bacteria that are capable of breaking down tough plant material into digestible form. Key Role Rodents often play a key role in the communities in which they live because they serve as prey for other mammals and birds. In this way, they are similar to hares, rabbits, and pikas, a group of mammals whose members also serve as prey for carnivorous birds and mammals.  To counterbalance the intense predation pressures they suffer and to maintain healthy population levels, rodents  must produce large litters of young every year. Key Characteristics The  key characteristics of rodents include: one pair of incisors in each jaw (upper and lower)incisors grow continuouslyincisors lack enamel on the back of the tooth (and are worn down with use)a large gap (diastema) behind incisorsno canine teethcomplex jaw musculaturebaculum (penis bone) Classification Rodents are classified within the following taxonomic hierarchy: Animals Chordates Vertebrates Tetrapods Amniotes Mammals Rodents Rodents are divided into the following taxonomic groups: Hystricognath rodents (Hystricomorpha): There are about 300 species of hystricognath rodents alive today. Members of this group include gundis, Old World porcupines, dassie rats, cane rats, New World porcupines, agoutis, acouchis, pacas, tuco-tucos, spiny rats, chinchilla rats, nutrias, cavies, capybaras, guinea pigs, and many others.  Hystricognath rodents have a unique arrangement of their jaw muscles that differs from all other rodents.Mouse-like rodents (Myomorpha) - There are about 1,400 species of mouse-like rodents alive today. Members of this group include mice, rats, hamsters, voles, lemmings, dormice, harvest mice, muskrats, and gerbils. Most species of mouse-like rodents are nocturnal and feed on seeds and grains.Scaly-tailed squirrels and springhares (Anomaluromorpha): There are nine species of scaly-tailed squirrels and springhares alive today. Members of this group include the Pels flying squirrel, long-eared flying mouse, Cameroon scaly-tail, East African springhare, and the South African springhare. Some members of this group (notably the scaly-tailed squirrels) have membranes that stretch between their front and hind legs that enable them to glide.Squirrels-like rodents (Sciuromorpha): There are about 273 species of squirrel-like rodents  alive today. Members of this group include beavers, mountain beavers, squirrels, chipmunks, marmots, and flying squirrels. Squirrels-like rodents have a unique arrangement of their jaw muscles that differs from all other rodents. Source: Hickman C, Roberts L, Keen S, Larson A, lAnson H, Eisenhour D.  Integrated Principles of Zoology  14th ed. Boston MA: McGraw-Hill; 2006. 910 p.